Evaluating human health risks from exposure to agricultural soil contaminants using one- and two-dimensional Monte Carlo simulations

The health and well-being of Indigenous Peoples are closely connected to the state of their lands. While natural soils are important for food security initiatives within these communities, they may also expose people to harmful contaminants. Consequently, this study - guided by Indigenous community members and leaders - evaluates the human health risks associated with contaminants in soils intended for agricultural purposes on Indigenous Peoples' lands in regions of Australia and Canada. Soil samples were collected from 47 sites in seven locations and analyzed for metals, metalloids, and organochlorine pesticides. Non-carcinogenic and carcinogenic risks were assessed for children, youths, and adults using one- and two-dimensional Monte Carlo simulations. The results indicate that there is a non-carcinogenic risk of exposure to lead (Pb) for children (HQ = 1.83) in Australia and an oral ingestion risk due to inorganic arsenic (As) for children (HQ = 1.05) in Newfoundland. Carcinogenic risks from As exposure were also identified for children (R = 1.68 × 10^-5) and adults (R = 1.18 × 10^-5) in Newfoundland from oral ingestion. However, no non-carcinogenic or carcinogenic risk from dermal exposure was found for all tested contaminants. The results indicate a potential need for targeted interventions, such as soil remediation, when and where possible, or community education, to reduce exposure risks.